These are resources for developers of QuickFIX/J, not the developers who use the tool.
Source code is available from the SourceForge Subversion repository. Information on accessing the repository can be found here. You can also browse the Subversion repository.
As the SourceForge Subversion documentation states, you'll generally want to checkout the trunk rather than the root of the repository.
svn co https://svn.sourceforge.net/svnroot/quickfixj/trunk quickfixj
There are two Eclipse plugins that can be used to access Subversion repositories. I (Steve Bate) have been using Subclipse, which is provided by the developers of Subversion. It works in a very similar way to the CVS plugin in Eclipse. The other plugin is called Subversive. I haven't used this one but if you've had experience with it, please add your experience to this page.
Jira is used for issue/bug tracking and release management. It can be found here.
Cruise control information is here.